1 files changed, 88 insertions, 0 deletions
diff --git a/plugins/shotwell-transitions/ChessEffect.vala b/plugins/shotwell-transitions/ChessEffect.vala
new file mode 100644
index 0000000..37c9fd2
--- /dev/null
+++ b/plugins/shotwell-transitions/ChessEffect.vala
@@ -0,0 +1,88 @@
+/* Copyright 2013 Jens Bav
+ * Copyright 2011-2014 Yorba Foundation
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+using Spit;
+
+private class ChessEffectDescriptor : ShotwellTransitionDescriptor {
+    public ChessEffectDescriptor(GLib.File resource_directory) {
+        base(resource_directory);
+    }
+
+    public override unowned string get_id() {
+        return "org.yorba.shotwell.transitions.chess";
+    }
+
+    public override unowned string get_pluggable_name() {
+        return _("Chess");
+    }
+
+    public override Transitions.Effect create(HostInterface host) {
+        return new ChessEffect();
+    }
+}
+
+private class ChessEffect : Object, Transitions.Effect {
+    private const int DESIRED_FPS = 25;
+    private const int MIN_FPS = 10;
+    private const int SQUARE_SIZE = 100;
+    private double square_count_x;
+    private double square_count_y;
+
+    public ChessEffect() {
+    }
+
+    public void get_fps(out int desired_fps, out int min_fps) {
+        desired_fps = ChessEffect.DESIRED_FPS;
+        min_fps = ChessEffect.MIN_FPS;
+    }
+
+    public void start(Transitions.Visuals visuals, Transitions.Motion motion) {
+      square_count_y = visuals.to_pos.height / SQUARE_SIZE + 2;
+      square_count_x = visuals.to_pos.width / SQUARE_SIZE + 2;
+    }
+
+    public bool needs_clear_background() {
+        return true;
+    }
+
+    public void paint(Transitions.Visuals visuals, Transitions.Motion motion, Cairo.Context ctx,
+        int width, int height, int frame_number) {
+        double alpha = motion.get_alpha(frame_number);
+        double size = 2 * alpha * SQUARE_SIZE;
+        if (visuals.from_pixbuf != null) {
+            Gdk.cairo_set_source_pixbuf(ctx, visuals.from_pixbuf, visuals.from_pos.x,
+                visuals.from_pos.y);
+            ctx.paint_with_alpha(1 - alpha);
+        }
+        
+        if (visuals.to_pixbuf != null) {
+            Gdk.cairo_set_source_pixbuf(ctx, visuals.to_pixbuf,visuals.to_pos.x, visuals.to_pos.y);
+            for (double y = 0; y <= square_count_y; y++) {
+                for (double x = 0; x <= square_count_x; x++) {
+                    double translation = (x+y) % 2 == 0 ? -1.5 * SQUARE_SIZE : 1.5 * SQUARE_SIZE;
+                    if (motion.direction == Transitions.Direction.FORWARD) {
+                        ctx.rectangle(visuals.to_pos.x + translation + x * SQUARE_SIZE,
+                        visuals.to_pos.y + y * SQUARE_SIZE, size, SQUARE_SIZE);
+                    } else {
+                        ctx.rectangle(visuals.to_pos.x + visuals.to_pos.width + translation - x
+                            * SQUARE_SIZE - size, visuals.to_pos.y + y * SQUARE_SIZE, size,
+                            SQUARE_SIZE);
+                    }
+                }
+            }
+
+            ctx.clip();
+            ctx.paint_with_alpha(alpha);
+        }
+    }
+
+    public void advance(Transitions.Visuals visuals, Transitions.Motion motion, int frame_number) {
+    }
+
+    public void cancel() {
+    }
+}